A Dynamic Model for the Evolution of Protein Structure

Area of Science:

• Evolutionary biology
• Structural bioinformatics
• Computational biology

Background:

• Protein domains are fundamental evolutionary units with hierarchical structures.
• Understanding their evolutionary dynamics is key to deciphering protein function and diversity.

Purpose of the Study:

• To develop global dynamical models for protein domain evolution at fold and fold superfamily levels.
• To analyze evolutionary rates and identify key transition periods.

Main Methods:

• Phylogenomic trees of domain structures from diverse genomes were used.
• Birth-death differential equations modeled domain evolution dynamics.
• Models were fitted to data, simplifying tree topologies for parameter estimation.

Main Results:

• Evolutionary rate constants for folds and fold superfamilies evolved similarly.
• A sharp transient change in these rates occurred approximately 1.5 billion years ago.
• This period correlates with massive domain combination and novel protein arrangement evolution.

Conclusions:

• Protein structure evolution is characterized by coarse-grained discoveries followed by fine-grained elaboration.
• The identified evolutionary shift highlights a critical period of protein innovation linked to organismal diversification.